One thing all battle droids had in common was that they had limited intelligence. They were programmed to follow orders, and not much else, though they did have personalities. Some battle droids however, had some form of intelligence. These droids were much more expensive to make, due to their advanced brains. Examples are the BX-series droid commando, the IG-100 MagnaGuard and, save for the first versions, the Droideka.